Support Induced Effects on the Ir Nanoparticles Activity, Selectivity and Stability Performance under CO2 Reforming of Methane

Nanomaterials

Dimitris I. Kondarides¹  Georgios Kyriakou¹  Kalliopi Kousi²  Richard M. Lambert³  Martin J. Taylor⁴  Paraskevi Panagiotopoulou⁵  Ioannis V. Yentekakis⁵  Grammatiki Goula⁵  Ersi Nikolaraki⁵ 

[1] Department of Chemical Engineering, University of Patras, GR 265 04 Patras, Greece;Department of Chemical and Process Engineering, University of Surrey, Guildford GU2 7XH, UK;Department of Chemistry, Cambridge University, Cambridge CB2 1EW, UK;Energy and Environment Institute, University of Hull, Hull HU6 7RX, UK;Laboratory of Physical Chemistry and Chemical Processes, School of Chemical and Environmental Engineering, Technical University of Crete, 73100 Chania, Crete, Greece;

关键词: greenhouse gases;    dry reforming of methane;    carbon dioxide;    alumina-ceria-zirconia mixed oxides;    iridium nanoparticles;    coking-resistant catalysts;   

DOI  :  10.3390/nano11112880

来源: DOAJ

【 摘 要 】

The production of syngas (H₂ and CO)—a key building block for the manufacture of liquid energy carriers, ammonia and hydrogen—through the dry (CO2−) reforming of methane (DRM) continues to gain attention in heterogeneous catalysis, renewable energy technologies and sustainable economy. Here we report on the effects of the metal oxide support ($\mathsf{\gamma }$-Al₂O₃, alumina-ceria-zirconia (ACZ) and ceria-zirconia (CZ)) on the low-temperature (ca. 500–750 ${}^{\circ }$C) DRM activity, selectivity, resistance against carbon deposition and iridium nanoparticles sintering under oxidative thermal aging. A variety of characterization techniques were implemented to provide insight into the factors that determine iridium intrinsic DRM kinetics and stability, including metal-support interactions and physicochemical properties of materials. All Ir/$\mathsf{\gamma }$-Al₂O₃, Ir/ACZ and Ir/CZ catalysts have stable DRM performance with time-on-stream, although supports with high oxygen storage capacity (ACZ and CZ) promoted CO₂ conversion, yielding CO-enriched syngas. CZ-based supports endow Ir exceptional anti-sintering characteristics. The amount of carbon deposition was small in all catalysts, however decreasing as Ir/$\mathsf{\gamma }$-Al₂O₃ > Ir/ACZ > Ir/CZ. The experimental findings are consistent with a bifunctional reaction mechanism involving participation of oxygen vacancies on the support’s surface in CO₂ activation and carbon removal, and overall suggest that CZ-supported Ir nanoparticles are promising catalysts for low-temperature dry reforming of methane (LT-DRM).

【 授权许可】

Unknown